This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The two-photon laser-scanning microscope available in our facility is equipped with dual galvonometeric laser scanners with each of these scanners independently directing two beams from ultrafast lasers. Both scanners are under the control of custom software allowing for simultaneous photo-release of various caged compounds and two-photon imaging of associated signals as well as electrical recordings. The combination of excellent spatial resolution, tissue penetration and low phototoxicity allows the microscope to be used in a wide range of experiments.